Copernicium (Cn)
“Made in Darmstadt on 9 February 1996 from zinc and lead, and named for Copernicus, the astronomer who moved the centre of the universe — predictions say this strangest of metals may barely want to stay solid at all.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
The notes
Characteristics
- A laboratory-only superheavy metal — copernicium is made by fusing zinc-70 with lead or other heavy targets, a few atoms per experiment at best.
- Relativity reshapes it like no lighter element: the 7s pair contracts so hard that chemists predict noble-gas-like behaviour instead of ordinary metal bonding.
- Its isotope Cn-285, arriving in decay chains from livermorium, survives around half a minute — among the longest lives of any superheavy element.
- Calculations foresee a colourless, volatile metal that could deposit on cold gold surfaces the way radon does — a property experimenters hope one day to test.
Copernicium has never been collected into a visible speck. Relativistic calculations predict something no metal manages elsewhere in the table: with its 7s electrons pulled tightly inward and a closed 6d shell, it should behave like a noble-gas-flavoured mercury — so weakly bound that it may be a volatile liquid, or even a gas, at room temperature.
Where you meet it
✦ Uses
- Copernicium’s long-lived isotopes anchor the upper end of known decay chains, letting physicists map how superheavy nuclei approach the predicted island of stability.
- Its predicted volatility makes it the flagship target for future gas-phase chemistry: an atom landing on a cold gold detector would prove superheavy “noble-metal-gas” behaviour.
- The zinc-plus-lead fusion route that built it remains a reference recipe for accelerator teams tuning beams in the quest for elements beyond 118.
◍ Everyday examples
- Chemistry students meet Cn as the textbook “what if” — the metal predicted to break the rule that metals stay put in a flask.
- It closes the Darmstadt dozen: between 1981 and 1996, GSI discovered elements 107 through 112, ending the run with copernicium.
- In decay-chain charts of livermorium and oganesson experiments, Cn-285 appears as the long-lived rung near the top of the ladder.
History & name
On 9 February 1996 Sigurd Hofmann’s GSI team fused zinc-70 with lead-208 and caught one atom of copernicium-277, its identity sealed by an alpha-decay chain into known nuclei. More atoms followed between 2000 and 2002, and after weighing rival claims IUPAC credited the Darmstadt group with the discovery in 2009. The name arrived in 2010 — copernicium, for Nicolaus Copernicus, the Renaissance astronomer whose heliocentric model displaced Earth from the centre of everything; the discoverers had pushed for the name since 2007, timing their proposal to the astronomer’s birthday, 19 February. The naming also settled a diplomatic detail: the symbol became Cn, since Cp had once served as cassiopeium, an old name for lutetium.